1. Technical Field
This invention relates to closure caps and corresponding neck finishes for edible products and the like that due to the product's nature allows in some instances for a self-unscrewing of the cap during shipping and storage. This "cap creep" phenomenon is often due to the product's viscosity that penetrates between the interlocking screw threads and reduces the frictional co-efficient therebetween allowing the cap to unscrew, "creep" and become loose over time and handling.
2. Description of Prior Art
Prior art devices of this type have used locking means to prevent rotation of the cap from neck finishes or more typically have relied on tamper evident designs to keep the cap secured until open. Such tamper evident caps are not necessarily effective since some designs still allow for cap "creep" within the confines of the secondary engagement cap portion required to remove the cap. Such examples of the preceding caps can be seen in U.S. Pat. Nos. 5,360,127, 5,685,445, 4,727,998, 4,664,273, 4,494,665, 4,345,691 and 4,270,666.
In U.S. Pat. No. 5,360,127 a non-removable container closure can be seen having interlocking ratchet teeth on both the cap and the neck finish of the container. Once the cap is threaded onto the container and the teeth engage, you cannot remove it without breaking a portion of the cap.
U.S. Pat. No. 5,685,445 is directed to an anti-backoff removable closure for a container having interengaging ratchet teeth on cap and neck finish. The cap teeth have a trailing edge that will "cam" sufficiently out of engagement with the neck finish.
A tamper evident closure can be seen in U.S. Pat. No. 4,727,998 wherein a cap has a tear tab and a frangible strip connecting it to the cap. The tear tab, once removed, will allow for reverse rotation and removal of the cap.
U.S. Pat. No. 4,664,273 claims a child resistant container and closure means having a series of large and small grooves in the cap portion and selectively registering projections on the neck finish.
U.S. Pat. No. 4,494,665 on a device for preventing the self-unscrewing of a cap from a container is shown having a projection on the neck finish over which the lower end of a cap screw thread rides holding the cap more securely in place.
U.S. Pat. No. 4,345,691 claims a child resistant closure for a pump dispensing device wherein a series of ratchet teeth on the inside of the cap engage registering teeth on the closure preventing the cap from being removed from the container.